Ruminant animal feed supplement

ABSTRACT

A process and feed composition for supplying fatty acids to ruminant animals which comprises feeding saturated fatty acids in the form of triglycerides to the animals. These highly saturated triglycerides may be added in an amount preferably between 2-5% of the total dry matter of the ratio. The highly saturated fatty acids according to the present invention have an iodine value of less than 25.

CROSS REFERENCE TO RELATED APPLICATIONS

This application .Iadd.is a reissue of 07/944,037, now U.S. Pat. No.5,206,041, which .Iaddend.is a continuation of U.S. Ser. No. 07/470,391,filed Jan. 24, 1990, now abandoned, which is a continuation of U.S. Ser.No. 07/272,095, filed Nov. 16, 1988, and issued as U.S. Pat. No.4,919,940.

BACKGROUND OF THE PRESENT INVENTION

The invention relates to a ruminant animal feed supplement and morespecifically to a supplement and feed process which permits ruminantanimals to be fed increased amounts of fatty acids in their diet whileprotecting the micro-organisms within the ruminants' stomachs fromattack by the fatty acids.

Ruminants, particularly dairy cattle, have high energy demands duringthe lactation period, especially during the first one-third of thelactation period. During these periods of higher milk production,conventional cattle feeds, such as corn and alfalfa, lack the energydairy cattle require. As a result, dairy cattle often do not maximizemilk yields during this period and also tend to lose body weight due toenergy deficiencies in the diet. Fat is an excellent source of energy,if digestibility problems which result from fat intake can be overcome.It has been suggested that, if the proportion of fat or fatty acids incattle feed, especially during the lactation period, could be increased,the cattle could produce higher milk yields with increased butter fatcontent without losing body fat and without diminishing the proportionof milk fat in the milk produced.

Recent articles including Pertelsen, A., Feedstuffs (Jun. 27, 1983);Jimenez. A A., Feedstuffs (Aug. 18, 1986); and Palmquist. D. L., AnimalHealth and Nutrition (Feb. 19, 1987) all recognize that the addition tofat or fatty acids to conventional dairy rations results in benefitswhich tend to relieve this energy shortage. However, conventional fats,such as tallow or animal fat, soybean oil, cottonseed oil, etc. tend tohave a deleterious effect on rumen microorganism populations if added atrates of more than 2-3%. The reason is that, as the supplement entersthe rumen, fatty acids attack the microbes which normally digest fiber,protein, and carbohydrates in the food. Without these microorganisms,decreases in milk production are likely to result.

As a result, the use of increased fats or fatty acids to the diet is notas simple as first appears. It is thought that conventional fatsinterfere with the digestability of feed components by (a) coating thefibrous portion of the diet with lipids which prevent attack bymicrobes; (b) modifying the rumen population concerned with cellulosedigestion; (c) inhibiting the activity of rumen microorganisms; or (d)reducing the retention of calcium due to excessive excretion of soap inthe feces. It is also been proven (Palmquist, D. L. and T. C. Jenkins,Journal of Dairy Science, 63:1 (1980) and Chalupa, W. et al., Journal ofDairy Science, 67:1439 (1984) and Chalupa, W. et al., Journal of DairyScience, 69:1293 (1986)) that "unsaturated" fats have more harmfuleffects than "saturated" fats. As used herein, the terms "unsaturated","saturated", and "highly saturated" should be defined. "Unsaturated"fats are those, such as soybean oil, which have an iodine value of 125or more. "Saturated" fats, such as tallow, are those having an iodinevalue in the range of 50. Even at this relatively low iodine value,tallow still contains more than one-half unsaturated fatty acids. Infurther discussion hereinafter, the term "highly saturated" will be usedto denote a product that has been chemically altered by being saturatedor hydrogenated to form a fat or fatty acid with an iodine value of 35or less. The iodine value is a measure of the liquidity of the fattyacid, the higher the value, the more liquid the material.

It has previously been proposed to protect the microorganisms in therumen from attack by fatty acids in various ways. First, fats have beencoated with proteins which were then treated with formaldehyde. Thesecross-linked proteins were "protected" from microbial digestion and theencapsulated fat escaped through the rumen to the abomasum and lowerdigestive tract. Recently, formaldehyde has been found to have adverseor undesirable physiological effects which preclude the use offormaldehyde and, therefore, the use of this method of providing proteincoated fats in dairy feeds.

Another approach involves the use of saturated (iodine value of 35-45)fatty acids in powdered form. Because of their relatively high meltingpoint, the saturated fatty acids move through the rumen without mucheffect on rumen microorganisms. (See Canadian Patent No. 1,187,732 toSchaub.) The products presently which include saturated fatty acids,however, have prices which cause them be economically marginal orunacceptable.

In the Palmquist et al. U.S. Pat. No. 4,642,317, issued Feb. 10, 1987,there is disclosed a process whereby calcium salts of fatty acids areused to supplement dairy rations. Fatty acids in the form of calciumsalts are inert in the rumen and have no apparent negative effects onfermentation. The high pH of the rumen allows these soaps (calciumsalts) to move through the rumen without effecting digestion after whichthey are subsequently split and digested. The Palmquist et al. techniquehas attained some popularity, however, its cost causes this technique tobe economically marginal.

In another approach, saturated fatty acids are formed by hydrogenationprocess and the glycerides or triglycerides are removed. It is thoughtthat these fatty acids, because they are in free fatty acid form, maystill be toxic to rumen microorganisms, although to a lesser extent thanunsaturated fatty acids or conventional fats. The resulting product hasachieved only limited success and further improvement is believednecessary before such approach becomes acceptable.

There is, therefore, a need for a feed supplement by which ruminants,particularly dairy cattle, can be fed fatty acids at economicallyproductive rates while protecting the rumen microorganisms from thedeleterious effects of the fatty acids.

SUMMARY OF THE PRESENT INVENTION

The present invention, in its broadest aspect, is directed to a processand feed supplement for supplying fatty acids containing at least 10carbon atoms to ruminant animals while protecting the microorganisms inthe rumen from attack by the fatty acids which includes the use ofhighly saturated fatty acids in the form of triglycerides along with thedry matter of the feed ration. By "highly saturated", it is meant thatthe iodine value of the fatty acids is less than 35 and preferably about20. This highly saturated fat in triglyceride form apparently insulatesthe microbes from the effects of the fatty acids until the feedsupplement has passed through the rumen and into the other parts of thecow's digestive system. The fatty acids are then freed to carry out thedesirable effect for the cow's body maintenance and milk production.

It has been found that any natural fat can be saturated (hydrogenated)to the extent that the iodine value is less than 35. However, economicstudies show that saturated fats such as tallow, lard, and grease arealready low in the iodine value and, therefore, are cheaper to saturate.Such fats also have cheaper raw material costs than unsaturated orhighly unsaturated fats such as soybean or cottonseed oil.

Hydrogenated fats are presently used for industrial purposes such astextile sizing compounds, mold release agents for plastics and rubber,and as reactants for the manufacture of surfactants. However, it is notbelieved that highly saturated fats (triglycerides) have been utilizedas feed supplements before. In fact, triglycerides have previously beenthought to be too indigestible for dairy rations (MacLeod andBuchanan-Smith, Journal of Animal Science, 35:890 and Palmquist, D. L.,Feedstuffs, (Apr. 30, 1979).

The addition of highly saturated triglycerides in accordance with thepresent invention increases the energy density of conventional feeds,particularly dairy feeds. Further, the following advantages are noted:

1. When compared to conventional fats, such as tallow and soybean oil,the feed supplement of the present invention is less likely to effectruminal microorganisms, thereby leaving such microorganisms unaffectedto carry out their intended digestibility effects on other feedcomponents in the ration.

2. When compared to other highly saturated free fatty acids, the feedsupplement of the present invention which utilizes the triglycerides hasa lesser effect on ruminal microorganisms and is more economical due toa lower cost per pound of fat.

3. When compared to the calcium salts of fatty acids, the presentinvention is more economical due to a lower cost per pound of fat.

4. When compared to conventional feeds without added fat at all, thepresent invention provides a higher energy density in the total dairyration thereby allowing for gains in milk production and total herdhealth, without adversely effecting the function of the ruminalmicroorganisms.

5. When compared to calcium salts of fatty acids, the present inventionprovides a feed supplement that contains no discernible taste differencesuch as occurs with the calcium salts.

The feed supplement of the present invention is fed to the animals in anamount of at least one percent of the dry solids weight of their feedand preferably in the range of 2-5%. Preferable triglycerides includesaturated tallow, lard, and grease because of the economies they afford.

It is therefore an object or the present invention to provide a higherenergy food supplement for ruminant animals which does not attack themicrobes of the animals' rumen.

It is another object of the present invention to provide a feedsupplement of the type described which results in an increased fatcontent in the animal's milk.

It is another object of the present invention to provide a feedsupplement of the type described which results in a greater milk yield.

It is yet another object of the present invention to provide a feedsupplement which combines the attributes of providing increasedproduction, higher fat content in the milk, protection of the rumenmicrobes, and enhanced economies.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Turning now to a preferred embodiment of the present invention, there isfirst provided a feed supplement which includes the use of highlysaturated fatty acids in the form of triglycerides. Such fatty acidsshould contain at least ten carbon atoms and preferably 10-24 carbonatoms. The selected fatty acids should either have an iodine value or besaturated to the point that the iodine value thereof is less than 35 andpreferably approximately 20. While any natural fat (which is generally amixture of several fatty acids having 10-24 carbon atoms) can besaturated by the process of hydrogenation to the extent that the iodinevalue is less than 35, in the case of unsaturated fats the procedure maybe expensive. However, certain saturated or highly saturated fats suchas tallow, lard, and grease, are already low in iodine value, easier tosaturate or hydrogenate, are more readily available, have lower coststhan higher iodine value vegetable oils, and are therefore moreeconomical in achieving the desired iodine value. The fats may consistof a mixture of fatty acids.

The above described feed supplement is utilized in a process forproviding fatty acids to ruminant animals in which the feed supplementis utilized in the form of triglycerides along with the dry matter ofthe feed ration. The feed supplement should make up at least one percentof the dry solid weights of the ration and preferably between 2-5%thereof. As the normal vegetable material in the animal's diet containsapproximately 2% fat, the total fat content of the diet provided by thefeed supplement will increase to 5-7%.

There results a cattle feed comprising at least one vegetable materialthat is edible by ruminant animals and the aforementioned highlysaturated triglycerides of fatty acids. The preferred vegetable materialinclude the group containing legume hay, grass hay, corn silage, grasssilage, legume silage, corn grain, oats, barley, distillers grain,brewers grain, soya bean meal, and cotton seed meal.

The invention will be further described by the following example:

Saturated triglycerides made from hydrogenated yellow grease were fed toeight lactating Holstein cows in a replicated 4×4 Latin Square todetermine the effect of the triglycerides on milk production, feedintake, and digestion. The yellow grease was hydrogenated to such apoint that the iodine value was approximately 5. Dietary treatmentsconsisted of a mixed ration (50% corn silage and 50% dry matterconcentrate). Diet C consisted of no fat supplement (control); diet YGconsisted of 5% yellow grease supplement; diet 3% HYG consisted of asupplement of 3% saturated triglycerides; and diet 5% HYG consisted of asupplement of 5% saturated triglycerides. Diets were fed ad libitum for21 day periods with milk and fecal grab samples collected the last fourdays of each period. Thus the test arrangement is as follows:

    __________________________________________________________________________    Cow #                                                                         Period                                                                            1    2    3    4    5    6    7    8                                      __________________________________________________________________________    1   C    YG   3% HYG                                                                             5% HYG                                                                             C    YG   3% HYG                                                                             5% HYG                                 2   YG   3% HYG                                                                             5% HYG                                                                             C    YG   3% HYG                                                                             5% HYG                                                                             C                                      3   3% HYG                                                                             5% HYG                                                                             C    YG   3% HYG                                                                             5% HYG                                                                             C    G                                      4   5% HYG                                                                             C    YG   3% HYG                                                                             5% HYG                                                                             C    Y    3% HYG                                 __________________________________________________________________________

The results of the digestibility tests are set forth below with thefigures representing the mean percentage of digestion of the eight cows:

    ______________________________________                                                 APPARENT DIGESTIBILITIES (%)                                                  Supplements                                                          Item       None   YG        3% HYG 5% HYG                                     ______________________________________                                        Dry Matter 70.0   72.0      69.6   68.7                                       Nitrogen   65.1   59.8      59.5   57.5                                       Energy     65.5   60.5      58.9   56.6                                       Fatty acids                                                                              73.2   67.8      53.6   47.4                                       ADF        31.6   21.6      18.9   20.0                                       ______________________________________                                    

Compared to the control and yellow grease, the dry matter digestibilitywas not significantly different. It is felt that an increase in iodinevalue to approximately 20 would show improved results in all areas.

The results of the milk yield and composition are set forth below, againthe figures representing the mean results from the eight cows:

    ______________________________________                                                 MILK YIELD AND COMPOSITION                                                    Supplements                                                          Item       None   YG        3% HYG 5% HYG                                     ______________________________________                                        Milk, kg/d 32.0   31.5      31.9   33.6                                       FCM, kg/d  29.6   25.9      28.8   32.3                                       Fat, %     3.50   2.83      3.34   3.74                                       Protein, % 3.20   3.07      3.17   3.09                                       Solids, %  12.43  11.64     12.22  12.59                                      Fat, kg/d  1.12   .88       1.07   1.26                                       Protein, kg/d                                                                            1.03   .96       1.01   1.04                                       Solids, kg/d                                                                             3.98   3.65      3.89   4.23                                       ______________________________________                                    

The results here for the 5% HYG are significant. A dairy farmer's incomeis predicated on the milk yield combined with the butter fat content(referred to as FCM (fat corrected milk) in the chart). The resultsindicate a gain of 6¢ per cow per day while on this feed program.

The results of the feed and energy intake are set forth below and is anindication of the cows' acceptance of the various diets:

    ______________________________________                                                 FEED AND ENERGY INTAKE                                                        Supplements                                                          Item       None    YG        3% HYG 5% HYG                                    ______________________________________                                        DM, kg/d   22.9    20.5      22.5   23.5                                      N, kg/d    .61     .56       .62    63                                        FA, kg/d   .61     1.42      1.34   1.77                                      ADF, kg/d  4.34    3.99      4.03   4.48                                      GE, Mcal/d 102.6   97.6      105.1  113.2                                     DE, Mcal/d 67.3    59.0      61.9   64.2                                      ______________________________________                                    

The resulting feed efficiency (Kg of FCM/kg of dry matter intake perday) shows that the 5% HYG diet feed efficiency is 1.37 compared to thecontrol group's efficiency of 1.29. This is significant.

The results of the ruminal fermentation set forth below is an indicationof the effect on ruminal microbes. One measure is the amount ofvolatile, fatty acids (VFA) produced which attack the rumen microbes,and the ratio of acetic to propionic (A/P) acids. As a result of a dietchange it is undesirable for the A/P ratio to drop. It is alsoundesirable for the protozoa population to diminish.

    ______________________________________                                                  RUMINAL FERMENTATION                                                          Supplements                                                         Item        None   YG        3% HYG 5% HYG                                    ______________________________________                                        VFA, mM     68.1   67.9      60.5   58.1                                      % of total VFA                                                                Acetic      59.9   57.7      60.9   62.6                                      Propionic   23.3   26.2      23.0   20.9                                      Isobutyric  .8     1.1       .8     1.0                                       Butyric     13.2   10.5      12.0   12.4                                      Isovaleric  1.3    2.0       1.6    1.7                                       Valeric     1.5    2.0       1.6    1.7                                       A/P         2.63   2.22      2.74   3.04                                      pH          6.75   6.77      6.88   6.97                                      Protozos    44.8   15.3      208.2  74.3                                      ______________________________________                                    

As evidenced here, the A/P ratio increases for both the 3% HYG and the5% HYG supplements. Also both supplements result in an increase in theprotozoa population.

Overall the tests show that both saturated triglyceraides result inincreased milk yield, milk fat content, and fat corrected milk yieldcompared to a commercial yellow grease supplement while causing fewernegative effects on feed intake and ruminal fermentation. In addition,the 5% HYG even compares more favorably to the control from thestandpoint of all tests except digestibility. It is believed that asupplement with an iodine value of 20 would significantly improvedigestibility.

It should be apparent that various changes and modifications might bemade in the type of fatty acids introduced, the percentage thereof, theiodine value thereof, and the dry matter of the diet without departingfrom so the scope of the invention which is set forth in theaccompanying claims.

What is claimed is:
 1. A process for supplying fatty acids containing atleast 10 carbon atoms to ruminant animals while protecting themicroorganisms in the animal's rumen from attack by the fatty acidscomprising feeding highly saturated fatty acids to said animals in theform of triglycerides along with the dry matter content of said animalfeed, said dry matter content including at least one vegetable materialedible by ruminant animals selected from the group including legume hay,grass hay, corn silage, grass silage, legume silage, corn grain, oats,barley, distillers grain, brewers grain, soya bean meal, and cotton seedmeal, said triglycerides being present in an amount effective to protectthe microorganisms in the animals' rumen from attack by the fatty acids,wherein the iodine value of said triglycerides is in the range of 5 to25.
 2. The process according to claim 1 wherein said saturated fattyacids comprise at least one percent of the dry matter content of saidanimals' feed.
 3. The process according to claim 1 wherein the saturatedfatty acids are provided in an amount equal to 2-5% of the dry mattercontent of said animals' feed.
 4. The process according to claim 1,wherein said saturated fatty acids are selected from the groupconsisting of . .natural fats and oils, including.!. tallow, lard, andgrease. . .5. A cattle feed consisting essentially of at least onevegetable material edible by ruminant animals selected from the groupincluding legume hay, grass hay, corn silage, grass silage, legumesilage, corn grain, oats, barley, distillers grain, brewers grain, soyabean meal, and cotton seed meal, and highly saturated triglycerides offatty acids, said triglycerides being present in an amount effective toprotect the microorganisms in the animals' rumen from attack by thefatty acids, wherein the iodine value of said saturated triglycerides isin the range of 5 to 25, which feed significantly improvesdigestibility..!.. .6. The cattle feed according to claim 5 wherein saidsaturated triglycerides comprise at least one percent of the dry mattercontent of said animals' feed..!.. .7. The cattle feed according toclaim 5 wherein the saturated triglycerides are provided in an amountequal to 2-5% of the dry matter content of said animal's feed..!.. .8.The cattle feed according to claim 5 wherein said saturatedtriglycerides are selected from the group consisting of natural fats andoils, including tallow, lard, and grease..!.